Science: Far-Out Moon

And maybe a new planet

It revolves around the sun at a mean distance of 5.9 billion km (3.7 billion miles) once every 248 years. Even in powerful telescopes, it is visible only as a fleck of light. Pluto, the solar system's ninth planet, was not discovered until 1930, and little is yet known about it. Now astronomers have learned surprising new things about the faroff planet: it appears to have a moon, seems to be much smaller than previously estimated and may some day be stripped of its title as the outermost member of the sun's family of planets.

While Astronomer James...

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